The present invention relates to a system and a method for controlling the release of an automatic parking brake device, on board an automobile.
The French patent application no. 2 828 450 (RENAULT) discloses a system for controlling the release of an automatic parking brake device, on board an automobile, wherein, if conditions representative of a hill start or maneuver are met, a command to release the parking brake is emitted a plurality of times, to actuators of the brakes, necessitating a multiple emission of a parking brake release command.
The patent applications GB 2 376 990 and GB 2 342 967 relate to the generation of a parking brake release command respectively according to the position of the clutch pedal and according to the torque measured on the wheels. These documents also include the emission of a parking brake release command a plurality of times.
These systems are not suitable for operating with brake actuators that require the sending of a single brake release command, notably because a multiple sending of a release command can lead to an excessive gap between the piston of a brake and the brake disc, allowing the possibility for foreign bodies such as dust to infiltrate therein, potentially causing an accelerated degradation of the brake. Furthermore, in the subsequent clamping, the clamping time of a brake is increased, because it is first of all essential for the piston to come back into contact with the disc, hence problems of noise and slowness of clamping.
Furthermore, such systems for controlling the release of an automatic parking brake device do not allow the driver to release the parking brake device at will, for example to deliberately delay the automatic release in the event of a hill start or a hill maneuver.